Climate change is one of the greatest
environmental, social and economic threats facing our planet.

Scientific
research has provided strong evidence for human-induced
climate change through a variety of methods, and studies
in all regions of the world continue to define the "spectrum
of concern" about climate change and its current
and future climate impacts. There is evidence that a
variety of impacts are already attributable to climate
change: changes in species behavior and lifecycle, rising
sea levels, retreat of glaciers worldwide, and additional
risks to human populations from heat-related impacts,
to name a few. Impacts are expected to intensify and
diversify as temperatures increase further.

However, future projections of climate
change and climate impacts are inherently uncertain, and often
that uncertainty paralyzes decision making or is used as a
reason to delay action. Uncertainty in forecasting of future
conditions or events is an accepted aspect of a variety of
political and financial decision making processes, and it
should not prevent society from making policy decisions now
to alter the trajectory of greenhouse gas emissions and climate
change. Instead, we must recognize that, while there is uncertainty,
we have enough information to begin to make educated guesses
about how much we should reduce greenhouse gas emissions,
and that the longer we delay, the more dangerous change becomes
likely.